Studies designed to characterize the cytology and synaptic organization of the basilar pontine nuclei in rats and cats will include the following: 1) Rapid Golgi and Golgi-Cox procedures will be used to analyze the cytologic features of individual pontine neurons. 2) Electron microscopic degeneration methods will be employed to study the morphologic features of basilar pontine synaptic organization. 3) Fundamental electrophysiologic studies will describe the response properties of pontine projection neurons and address certain intrinsic synaptic circuits. 4) The morphology and synaptology of individual pontine neurons will be described using the combined Golgi-EM technique as well as intracellular HRP injection.